Related Experiment Video
Updated: Nov 8, 2025
Multilevel Oblique Lumbar Interbody Fusion in Degenerative Lumbar Disc Disease with Instability
Published on: July 25, 2025
Constrained liners revisited: favourable mid-term results in patients with high-risk of dislocation: technical
Eustathios Kenanidis1,2, Panagiotis Kakoulidis1,2, Panagiotis Anagnostis1,2
1Academic Orthopaedic Department, Aristotle University Medical School, General Hospital Papageorgiou, Thessaloniki, Greece.
Insights
Constrained liners (CLs) in total hip arthroplasty (THA) show mid-term success in high-risk patients, improving stability and function. Careful patient selection and surgical technique are key to maximizing outcomes for these CLs.
Area of Science:
- Orthopedic Surgery
- Biomaterials Science
Background:
- The efficacy of constrained liners (CLs) in total hip arthroplasty (THA) is not definitively established.
- This study evaluates mid-term outcomes of CLs in high-risk patients undergoing primary or revision THA.
Purpose of the Study:
- To assess the survival rates, dislocation rates, complications, and functional outcomes of CLs in THA.
- To review surgical techniques that may enhance outcomes in these selected patient populations.
Main Methods:
- Retrospective evaluation of 45 patients who received Trident Tripolar CLs between 2010-2019.
- Inclusion criteria: primary or revision THA with high dislocation risk (e.g., abductor insufficiency, recurrent dislocations).
Main Results:
- Cumulative 6-year survival rate was 93.3% (100% primary, 89.3% revision).
- Two dislocations and one deep infection occurred in the revision group.
- Significant improvement in postoperative functional scores (p < 0.001).
Conclusions:
- CLs offer mid-term hip stability and fixation in selected low-demand, high-risk THA patients.
- Optimal outcomes require careful patient selection and refined surgical techniques, including neutral liner positioning and managing potential impingement.
Background:
The outcomes of constrained liners (CLs) in total hip arthroplasty (THA) remain inconclusive. We evaluated the mid-term performance of CLs in a consecutive series of high-risk dislocation patients undergoing primary or revision THA performed by a single surgeon. The survival, dislocation rate, complications, and functional patients' scores were assessed. Surgical tips to enhance outcomes were reviewed.
Methods:
45 patients who received the Trident Tripolar CL between 2010 to 2019 were retrospectively evaluated from Arthroplasty Registry Thessaloniki. There were 17 primary and 28 revision THAs. The primary indications for using CL were severe abductor insufficiency or comorbidities, increasing the dislocation risk in primary, and recurrent dislocation or abductor insufficiency in revision THAs. The mean patient's age was 68.5 (±14.5) years, and the mean follow-up 3.81 (±1.66) years.
Results:
There were 2 dislocations and 1 deep infection in the revision group. For any reason, the cumulative 6-year survival rate was 93.3%, 100% for primary, and 89.3% for revision THAs. The mean overall CL survival was 76.3 months for any reason (95% CI, 68.1-84.5) and 80.5 months for dislocation (95% CI, 75.8-85.2). The mean postoperative functional scores were significantly improved (p < 0.001) at the latest follow-up.
Conclusions:
CLs can provide hip stability and durable fixation in selected low-demand patients with high-risk for dislocation after primary and revision THA at mid-term follow-up. Careful patient selection and the refined surgical technique aiming at the neutral liner position and considering the high CLs' offset relative to stem-neck impingement are necessary to maximise outcomes.
More Related Videos
04:41Treatment with Locking Intramedullary Nailing for Intertrochanteric Fracture of the Femur Utilizing a New Awl with a Distal Positioner
Published on: June 6, 2025
08:40Author Spotlight: A Novel 3D-Printed Titanium Implant for Minimally Invasive Treatment of Hip Dysplasia in Young Dogs
Published on: April 19, 2024